1. Field of the Invention
The present invention relates to an improvement in a spacer for wiring boards such as print circuit boards for securing a suitable space between a plurality of wiring boards and for fixing the wiring boards when using a plurality of wiring boards or print circuit boards in a stacked condition, and also relates to an assembled structure thereof.
2. Description of the Prior Art
Heretofore, in electronic apparatuses, when mounting a wiring board or boards on a chassis or when mounting another wiring board or boards on one wiring board, support members are used which are secured between the wiring boards and a chassis or between the wiring boards by screws so that a number of steps are required for the operations of mounting the wiring boards, and also there is a disadvantage of high costs for mounting parts as a lot of parts are used.
As an improvement for overcoming these disadvantages, a spacer such as disclosed in the U.S. Pat. No. 3,836,703 has been proposed, which is integrally formed by using synthetic resin and which can be secured on a chassis or a wiring board in one step by using the resiliency of the synthetic resin and by snap-fitting the same.
Although there were, to be sure, some improvements in the reduction of the number of mounting steps and the cost thereof in the spacer disclosed in this patent compared with the one in which screws and support members are used, it had also a drawback that it had low mechanical strength against a load applied to the board in the horizontal direction or a load applied in the direction of twisting because of its rectangular form with substrates placed opposite to each other, with two side plates tying or bridging the substrates in order to retain the space between the wiring boards, thus resulting in a tendency for the support members to fail when only a small load is applied thereto.